She is sharing her story in a bid to help and inspire other women living a life she managed to escape.
"I'd tried to leave him on a number of occasions before, but had always gone back, believing the apologies, believing things would be better, believing this time would be different," she told the Herald.
But she was approaching a birthday and did not want to start another year "so unhappy".
Subritzky is now happily married, but she describes a previous relationship, after her first marriage broke up, as abusive and terrifying.
She said that at first things were great but after the relationship became more serious, things began to change.
"My partner was often irrational and volatile, and very possessive.
"If I was out, I would be bombarded with texts and calls; if I said I would be home by a certain time, and was even five minutes late, there would be hell to pay.
"My emails and phone records were monitored.
"If I met a friend for coffee, my partner would turn up."
Lorna Subritzky. New Zealand Herald photograph
She said there was also physical violence.
"I was once knocked unconscious by a head butt," she said.
"But mostly the abuse was psychological and I think that was far more damaging.
"My life was constantly walking on eggshells, and that is exhausting.
"I was belittled, gradually isolated from my friends and family, and threatened that if I ever left him, my life would not be worth living."
Subritzky said she felt "trapped" in the relationship.
"I felt terrible lying to friends and family about how happy my relationship was - and lying about how that enormous bruise on my arm was caused," she said.
"I felt ashamed - that someone of my intelligence and financial means could find myself in this situation and have no idea how to change it.
"I felt at times that somehow it was my fault, that perhaps if I was a better person then I would be treated better.
"Mostly I felt tired. Tired from having to watch everything I said and did, tired from trying to please - so tired I couldn't contemplate how I might find the energy to leave, and face the inevitable maelstrom that would result."
She knew she was finally ready to leave him - and that she had to leave - after a gathering with friends where her partner was "incredibly obnoxious" to everyone.
"My friend convinced me to stay the night at her house; even though I knew there would be hell to pay for this 'lack of obedience', I did it," she explained.
"We stayed up late talking about the situation - she had been in a similar relationship in the past and had some great insights.
"She also refused to allow me to make excuses for my partner - essentially, she showed tough love and it worked.
"It still took several months for me to summon the courage and energy to make the break, but it was certainly the important first step.
"In the end, I drove to my parents house one day and said "you have to help me leave this relationship".
"Their relief was palpable - they'd been waiting for this day for a long time."
Subritzky decided to share her personal story on air after a story was published about refuges being at capacity.
She said that story provided her with an opportunity to talk about domestic violence. New Zealand has the worst rate of domestic violence in the developed world.
"In order to have that conversation honestly, I felt it was important to share my own story, even though I have chosen to never speak about it publicly until now," she said.
"I think many people have a picture of what an abused woman looks like, and I think we need to realise victims can come from any socio-economic group, from any background - as can abusers, of course.
"I think we also need to understand that abuse can come in many forms - physical violence is just one."
Listeners reacted positively and Subritzky became emotional at some of the feedback.
"Perhaps most rewardingly, a man who was listening while working on the farm, and recognised he was an abuser - even though he'd never considered that possibility before," she said.
"He has a counselling session booked on Monday - that text made me cry."
NewstalkZB host Lorna Subritzky. New Zealand Herald photograph
Subritzky said it was crucial to raise awareness about family violence.
"Until we understand the prevalence and causes of domestic violence, we will struggle to find the solutions," she said.
"We need to recognise the symptoms of an abusive relationship, whether it be our own or that of a friend or family member, so we can provide support to each other.
"We have the worst record of domestic violence in the world - its our national shame and we - all of us - need to be part of the solution."
She had a message for people - women and men - who were experiencing abuse within their relationships.
"Life can - and should - be better," she said.
"You deserve more.
"Leaving is hard, but staying is ultimately going to kill you - literally or figuratively, certainly psychologically..
"Once you make that decision to leave though, you will feel a huge weight start to lift.
"Plan your exit - how, when, who can help you, whether or not you need a safe house; planning makes it less likely that you will return.
"Talk to a trusted friend, or a trained professional - here are resources available to you. "But be sure to keep yourself safe.
"Victims are at their most vulnerable when they make that final decision.
"I know how hard it is to leave - but you can, and life will be so much better when you have."
If you're in danger now:
• Phone the police on 111 or ask neighbours of friends to ring for you. • Run outside and head for where there are other people. • Scream for help so that your neighbours can hear you. • Take the children with you. • Don't stop to get anything else. • If you are being abused, remember it's not your fault. Violence is never okay
• Women's Refuge: Free national crisis line operates 24/7 - 0800 refuge or 0800 733 843 www.womensrefuge.org.nz • Shine, free national helpline 9am- 11pm every day - 0508 744 633 www.2shine.org.nz • It's Not Ok: Information line 0800 456 450 www.areyouok.org.nz • Shakti: Providing specialist cultural services for African, Asian and middle eastern women and their children. Crisis line 24/7 0800 742 584 • Ministry of Justice: www.justice.govt.nz/family-justice/domestic-violence • National Network of Stopping Violence: www.nnsvs.org.nz • White Ribbon: Aiming to eliminate men's violence towards women, focusing this year on sexual violence and the issue of consent. www.whiteribbon.org.nz
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